package com.Maath;

import java.util.Scanner;

public class Demo1 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个数");
        int a = sc.nextInt();
        double d = Math.PI * Math.pow(a, 2);
        System.out.println(d);
        double d1 = Math.floor(d);
        System.out.println(d1);
    }
}
